The present invention relates generally to cell selection in a packet communication system having a radio part, such as a WIO (wireless intranet office). More particularly, the present invention relates to a manner by which to utilize packet network quality as an indicia of the cell selection. Improved communication quality is possible in such a system as cell selection takes into account quality indicia of a packet network in addition to, or alternate to, quality indicia of the radio part of the communication system.
New types of communication systems have been made possible as a result of advancements in communication technologies. Such new types of communication systems have generally permitted increased rates of data transmission and corresponding amounts of data to be communicated in such new communication systems.
The advancements in communication technologies have, for example, permitted the introduction, and popularization, of new types of radio communication systems. Radio communication systems are advantageously utilized as communication paths formed during operation thereof include radio links. By utilization of radio links to form at least portions of the communication paths upon which information is communicated, the use of such portions of the communication paths do not require conventional wirelines. Increased communication mobility, relative to conventional wireline communication systems, is thereby generally possible in a radio communication system.
The communication capacity of a radio communication system, however, is sometimes limited by bandwidth limitations. That is to say, generally, only a limited spectrum allocation is provided to a radio communication system. Communication channels are defined within the allocated spectrum. And, communication signals are communicated upon the communication channels during operation of the radio communication system. However, because the spectrum allocation to the system is limited, the communication capacity of the communication system is sometimes limited by the amount of spectrum allocated to the system. Without additional spectrum allocation to the system, communication capacity of the system is possible only by utilizing more efficiently the allocated spectrum.
Digital communication techniques provide a manner by which to increase the bandwidth efficiency of communication in a communication system. The use of digital techniques is particularly advantageously utilized in a radio communication because of the limited spectrum typically allocated to such a system.
Information which is to be communicated in a communication system which utilizes digital communication techniques, typically, digitizes the information to form digital bits. The digital bits are typically formatted according to a formatting scheme. Groups of the digital bits, for instance, are positioned to form a packet, and, one or more packets of data together form a frame of data.
Because packets, or frames, of data can be communicated at discrete intervals, rather than continuously, a frequency band need not be dedicated solely for the communication of data between one communication pair. Instead, the frequency band can be shared amongst a plurality of different communication pairs. The ability to share the frequency band amongst more than one communication pair permits a multiple increase in the communication capacity of the system.
Packet data communications are effectuated, for instance, in conventional LANs (local area networks). Wireless networks, operable in manners analogous to wired LANs, referred to as WLANs (wireless local area networks) have also been developed and are utilized to communicate data over a radio-link. Packet communication systems, such as a LAN or WLAN, were generally initially installed to provide non-realtime data communications. But, with continued advancements in digital communication techniques, packet communication systems are increasingly installed to permit realtime communications. Telephony over IP (Internet protocol), e.g., voice communication by way of the Internet, or other packet data network backbone, is provided for in such systems.
A WIO (wireless intranet office) is exemplary of a packet radio communication system which is intended to provide voice, and other realtime, communications. Voice communications by way of a WIO provides the advantages of use of a wireless communication system in a cost-effective manner. Voice, as well as other data, can be communicated between mobile terminals operable in such a system. Various aspects of conventional cellular, or microcellular, communication systems are conventionally utilized in a WIO system.
For instance, in manners analogous to existing cellular communication systems, cell selection is made responsive to determination of radio link quality of the radio link extending between the mobile terminal and network infrastructure. Because other portions of a communication path conventionally extend to a fixed network, conventional systems do not generally consider the communication quality of the fixed network.
In contrast, in a WIO system, or other packet data network, different radio base stations might utilize different packet data networks, or portions thereof, through which to form a communication path. The different packet data networks might have differing levels of communication quality therethrough. Existing systems, however, do not take into account the packet network quality when determinations are made for purposes of cell selection. Cell selection might be made to have a mobile terminal, in either an idle or active mode, to be tuned-to, or xe2x80x9ccamp inxe2x80x9d a cell which, while exhibiting good. radio link qualities, exhibit poor packet network qualities. Communication quality levels would suffer as a result.
If a manner could be provided by which to take into account packet network quality when making cell selection, improved communication quality levels of communications in such a system would result.
It is in light of this background information related to packet communication systems that the significant improvements of the present invention have evolved.
The present invention, accordingly, advantageously provides apparatus, and an associated method, by which to utilize an indicia of packet network quality during cell selection procedures in a packet radio communication system. In contrast to conventional packet radio communication systems which utilize only indicia of radio link quality levels, improved communication quality is possible through operation of an embodiment of the present invention. Communication quality levels in a packet data network to which a radio base station is coupled is taken into account during cell selection procedures.
In one aspect of the present invention, cell selection is made responsive to determination of the radio link quality and also responsive to the packet network quality to which a radio base station is coupled and through which a communication path would be formed pursuant to a communication session. If the radio link quality is of a level at least as great as a selected threshold, cell selection is made responsive to packet network quality levels of the cells available for selection. If, however, the radio link quality is less than the threshold level, the cell associated with the radio link exhibiting the poor radio link quality is not further considered in the cell selection process. Thereby, cell selection is made on the basis of the packet network quality as long as the radio link quality is at least as good at the threshold level.
In another aspect, an embodiment of the present invention is operable in a WIO (wireless intranet office) system. In the WIO system, a plurality of radio base stations are positioned throughout an area to permit wireless communications in the area encompassed by the plurality of radio base stations. Each radio base station defines a cell, and various of the cells, such as adjacent cells, include overlapping areas. When a mobile terminal is positioned at a location at which more than one cell overlaps, the mobile terminal is able to tune to, i.e., camp-on, a radio base station which defines either of the cells. Cell selection is performed to determine which of the radio base stations to which the mobile terminal camps.
An embodiment of the present invention provides a manner by which to select the cell to which the mobile terminal camps. The determination is made, for instance, to ensure better the best quality of communications with the mobile terminal. Indicia of the quality of the radio link extending between the mobile terminal and the radio base stations as well as indicia of the communication qualities in the portions of packet data networks to which the radio base stations are coupled are utilized in making the determination. To be selected, the radio link must exhibit a quality level at least as good as a minimum threshold level and the packet network communication quality level exhibits the best of the available selections. By performing cell selection according to an embodiment of the present invention, improved communication quality is possible. Also, because the communication quality of the packet network is taken into account, occurrences of hand over, required when packet network quality is below a minimum level, are decreased. And, system resources are better utilized.
In another aspect of the present invention, apparatus is provided for an IMC (intranet mobile cluster) which forms a portion of a WIO system. An IMC is associated with each radio base station of the WIO system. Apparatus of an embodiment of the present invention is coupled to receive values representative of radio link quality levels of a radio link formable between the radio base station associated therewith and a mobile terminal. And, the apparatus is coupled to receive values representative of packet network communication quality of a packet network to which the IMC is also coupled. Signals representative of such values are provided to a mobile terminal.
In another aspect of the present invention, apparatus is provided for a mobile terminal operable in a WIO system. The mobile terminal is operable to receive signals generated by various radio base stations indicating radio link quality and packet network quality values. Responsive to detection of such signals, determination is made at the mobile terminal to which of the radio base stations that the mobile terminal should xe2x80x9ccamp-on.xe2x80x9d The mobile terminal is further operable to generate signals indicative of such determination so that appropriate actions can be performed by the network infrastructure of the system.
In these and other aspects, therefore, apparatus, and an associated method, is provided for a mobile communication system having a mobile terminal positionable to be operable to communicate alternately by way of a first radio base station upon a first communication path with a correspondent entity and by way of at least a second radio base station upon at least a second communication path with the correspondent entity. The first communication path extends through a first packet data network, and the second communication path extends through a second packet data network. Determinations are made of a preferred communication path of the first and at least second communication paths upon which to communicate information. A detector is at least coupled to receive indications of a first packet-network indicia of communication quality through the first packet data network. The detector is at least further coupled to receive indications of a second packet-network indicia of communication quality through the second packet data network. The detector forms a first communication path quality value responsive, at least in part, to the first packet-network indicia of communication quality and a second communication path quality value responsive, at least in part, to the second indicia of communication quality. A determiner is coupled to receive the first communication path quality value and the second communication path quality value. The determiner determines the preferred communication path responsive thereto.
A more complete appreciation of the present invention and the scope thereof can be obtained from the accompanying drawings which are briefly summarized below, the following detailed description of the presently-preferred embodiments of the invention, and the appended claims.